1. Field of the Invention
This invention relates to a family of side-chain homopolymers of the polyacrylate type derived from 1-(phenyl)-2-(4-cyanophenyl)-ethane and exhibiting one or a number of mesophases.
2. Description of the Prior Art
Increasing consideration is being given at the present time to the possibility of utilizing polymeric materials in devices relating to the field of nonlinear optics or to the display field. The use of these polymers in display devices is subject to two conditions: they must have high dielectric anisotropy and also a nematic mesophase. There also exist, however, experimental display systems in which a smectic-A polymer is employed. Polymers having both these characteristics are in steadily increasing demand. A polymer of this type which possesses in addition a glass transition temperature of higher value than room temperature can advantageously be employed in the field of nonlinear optics.
In order to satisfy these requirements, the invention proposes a family of homopolymers which exhibits high dielectric anisotropy due to the presence of a cyano group which produces at least one nematic mesophase at a high dipole moment and also, in the case of certain members of this family, gives rise to a glass transition temperature which is higher than room temperature.